When a child on a bicycle is struck by oncoming traffic, the results can be devastating. From life-threatening head injuries to bone fractures, the children are definitely the losers. As it turns out, their bodies heal faster than their minds.

Posttraumatic stress disorder (commonly known as PTSD) is a severe anxiety disorder characterized by adverse anxiety-related experiences, behaviors, and physiological responses that results from exposure to an event that causes psychological trauma. Examples of events that could lead to PTSD include the threat of harm or death to oneself or to someone else, or witnessing an event that overwhelms the individual's ability to cope. Diagnostic symptoms for PTSD include flashbacks or nightmares,...

A pivoted catch designed to fall into a notch on a ratchet wheel so as to allow movement in only one direction (e.g. on a windlass or in a clock mechanism), or alternatively to move the wheel in one direction.